When a vehicle is to move across water, the most common technique is to provide a floatable vehicle, and to use some means for propelling the vehicle through the water. The difficulty with this arrangement is that the drag on the vehicle increases as the length of the water line increases, so very large motive forces are required to move a large vehicle at even slow speeds.
The most common effort to solve the problem of the slow speed of a water going vehicle, other than by simply increasing the available power, has been to provide a more effective propelling means so that various screw-type propellers, paddle wheels, and the like have been devised. While such improved propelling means may deliver more of the available power to the vehicle, the large amount of drag on the vehicle still prevents very great speeds for large vehicles and requires a lot of power. Another means for solving the problem of the slow speed of a water-going vehicle is to provide foils so the vehicle can ride on the water foils, thereby reducing the drag and allowing the vehicle to move at relatively high speeds. While the use of foils has indeed allowed vehicles to attain high speeds, it is difficult to provide the strength necessary to support foils on a large vessel because of the stresses involved. In addition, an extremely large motive force is required to propel the vehicle fast enough for the vehicle to rise from the water to be supported solely by the foils.
Another attempt at solving the problem of moving a vehicle through water has been the use of a wheel-type propelling means wherein rapidly rotating paddle members exert flotation forces to cause the vehicle to rise in the water, and exert propelling forces to urge the vehicle along in the water. While several such devices have been provided in the past, none has achieved any noticeable commercial success. Such prior art water wheels have utilized, variously, hollow drums to assist in flotation, moveable paddles to assist in providing propelling forces, and other such apparatus. One of the primary problems with water wheels of this general variety is that the water wheel is not effective except at relatively high speeds, and most of the prior art water wheels would come apart at the required high rotational speeds. Also, such a water wheel must act against the water; therefore, if the paddle members of the water wheel agitate the water to the point that the water wheel is immersed in a froth, the water wheel loses its effectiveness. Another common problem with such water wheels is the lack of lateral stability. Side plates have been used on some water wheels, but such plates would allow air pockets between the paddle members and otherwise restrict water flow which severely diminishes the effectiveness of the water wheel.